<form action="postnumre.php">
	Postnummer:<input type="text" name="Postnummer" /> <br />
    By:<input type="text" name="By" /> <br />
    <input type="submit" value="OK" />
    </form>
<?php

	if(isset($_REQUEST["Postnummer"])){
		$c = mysqli_connect("localhost","root","","magnus-adressedatabase");
		$q = "insert into Postnummer values($_REQUEST[Postnummer],'$_REQUEST[By]')";
		$r = mysqli_query($c,$q);
	}
	
	$c = mysqli_connect("localhost","root","","magnus-adressedatabase");

	$q = "select * from postnummer";
	
	$r = mysqli_query($c,$q);
	
	while($record = mysqli_fetch_array($r)){
		echo "$record[Postnummer] $record[By] <br>";
	}
?>